Multilayered color photographic material with improved stability under tropical conditions

ABSTRACT

1. A COLOR-PHOROGRAPHIC MULTIAYER MATERAL HAVING COMPOUNDS THAT PRODUCE A NEGATIVE IMAGE BY IMAGEWISE EXPOSURE FOLLWED BY DEVELOPING TREATMENT OR REVERSAL TREATMENT PRODUCING POSITIVE IMAGE COMPRISING AT LEAST ONE RED-SENSITIZED SILVER HALIDE EMULSION LAYER CONTAINING A CYAN-FORMING COUPLER, AT LAST ONE GREEN-SENSITIZED SILVER HALIDE EMULSION LAYER CONTAINING A MAGENTA-FORMING COUPLER AND AT LEAST ONE BLUE-SENSITIVE SILVER HALIDE EMULSION LAYER CONTAINING A YELLOW-FORMING COUPLER, WHEREIN THE IMPROVEMENT COMPRISES AT LEAST ONE OF THE EMULSION LAYERS OF THE GROUP CONSISTING OF GREEN-SENSITIZED AND REDSENSITIZED EMULSION LAYERS COMPRISES IN THE SAME PHASE A BINDER, A SILVER IODOBROMIDE COLLODIAL SILVER AND THE COLOR COUPLER.

United States Patent MULTILAYEREI) COLOR PHOTOGRAPHIC MATE- RIAL WITHIMPROVED STABILITY UNDER TROPICAL CONDITIONS Hugo Zorn,Munich-Lochhausen, Helmut Broil, Munich, and Erich Reckziegel,Leverkusen, Germany, assignors to Agfa-Gevaert Aktiengesellschatt,Leverkusen, German No i Drawiug. Filed Oct. 4, 1972, Ser. No. 294,955Claims priority, application Germany, Oct. 6, 1971, P 21 49 837.3 Int.Cl. G03c 1/76, 3/00 US. Cl. 96--'74 3 Claims ABSTRACT OF THE DISCLOSUREStability to tropical conditions of color photographic multilayermaterials comprising blue, green and red sensitive silver halideemulsion layers and color couplers therein, is improved if the redsensitized and/ or the green sensitized silver halide emulsion layercontains colloidal silver.

This invention relates to a multilayered color photographic materialwhose stability under tropical conditions is improved by the addition ofcolloidal silver to at least one spectrally sensitized silver halideemulsion layer.

In order to enable photographic films to be stored under mild climaticconditions or at elevated temperatures, the necessary stability can beachieved by after-ripening the silver halide emulsions and by addingstabilizers such as mercapto compounds, organic disulfides, alkali metalthiosulfate complexes or triazaindolizines to the emulsions beforecasting the emulsions on a layer support. In many cases, particularly incolor photographic films, these measures are not sufficient to ensurethat the material will be stable when stored under tropical conditionswith high humidities.

It has now been found that the stability of multilayered colorphotographic material against tropical conditions can be improved if atleast one of the two silver halide emulsion layers which containcolor-forming couplers and are sensitized to the red or green region ofthe spectrum respectively contains colloidal silver.

It is thought that this stabilizing efiect is due to the colloidalsilver protecting the sensitivity centres against the action oftemperature and atmospheric moisture. In principle, any form ofcolloidal silver would have the effect required according to theinvention but the yellow form dispersed in gelatin, so-called yellowsilver, is pre ferred because it is almost completely transparent to redand green light and absorbs only blue light which is unwanted in thecyan-forming and magenta-forming layers. The blue sensitiveyellow-forming layer, whose sensitivity would be reduced to a greaterextent by the yellow silver, is in most cases much more resistant totropical conditions than the cyan-forming and the magenta-forming layerand therefore generally, does not need stabilization with yellow silver.The quantities of colloidal silver to be added depend on the degree towhich the stability under tropical conditions is required to beincreased. In practice, it has been found that quantities of between0.02 and 0.8 g. of colloidal silver per mol of silver halide arenecessary in the emulsion to achieve the stabilizing effect. Thesequantities have little or no effect on the maximum reversal colordensity. The preparation of various types of colloidal silver has beendescribed in the literature, e.g. in Weisers Colloidal Elements, Wiley &Sons, New York, 1933, which describes the preparation of yellowcolloidal silver by the dextrin reduction method of Carey Lea, in GermanPat. No. 1,096,193 (colloidal brown and black silver) and in US Pat. No.2,688,601 (colloidal blue silver).

3,846,133 Patented Nov. 5, 1974 The invention is explained with the aidof the following examples which demonstrate the colloidal silver ofvarious forms is suitable for improving the stability under tropicalconditions regardless of the nature of the emulsion, of the colorcoupler and of the method of color development, whether it be reversaldevelopment or negative development.

EXAMPLE 1 Starting with a highly sensitive silver iodobromide emulsionwhich has been sensitized to the red region of the spectrum and whichcontains 5 mols percent of AgI, and 100 g. of1-hydroxy-N-octadecyl-Z-naphthamide per mol of silver halide ascyan-forming coupler three samples containing 0, 0.4 or 0.16 g.respectively of colloidal yellow silver per mol of silver halide werecast on a layer support of cellulose acetate. The silver content of thelayer was 2 -g./m. From each sample, an unexposed strip *was stored for7 days under conditions simulating a tropical climate, the temperaturebeing 35 C. and the relative atmospheric humidity These strips and acorresponding strip of each sample which had not been stored in atropical cupboard were exposed through a grey sensitometer wedge. Thesample were developed by a process of color reversal development asfollows:

(1) First development: 12 minutes at 24 C. in a thiocyanate-containingmetol-hydroquinone developer of the following composition:

Sodium ethylene diaminotetraacetate g 2 p-N-monomethylaminophenolsemisulfate g 4 Sodium sulfite g 50 Hydroquinone g 6 Sodium carbonate g35 Sodium thiocyanate :g 1.5 Potassium bromide g 2 Potassium iodide g 10Benzotriazole mg 250 Made up with water to 1000 ml.

(2) Washing: 5 minutes.

- (3) Second exposure: 1 minute.

(4) Reversal development: 15 minutes at 24 C. in a color developer ofthe following composition:

Nitrilotriacetic acid g 2 Sodium sulfite g 5 Hydroxylarnine sulfate g 1Trisodium phosphate g 20 Potassium bromide g 1 Potassium iodide mg 10 4amino 3 methyl N ethyl N (ti-methylsulfonamidoethyl-anilinosesquisulfate monohydrate g 9 50% ethylene diamine ml 6 Made upwith water to 1000 ml. pH 12.0.

The samples were then treated by the usual methods of clarifying,bleaching the silver, fixing and washing. The developed strips wereassessed in a Macbeth densitometer behind a red filter.

The following table shows the specific sensitivity Ss=log I -t for thecolor density CF (C =color fog at total exposure) and the maximum colordensity D,,,,,, as well as the changes in these values AS and ADobserved after storage under tropical conditions.

TABLE 1 G. of colloidal silver per mol of silver halide--." 0. 04 0. 16

S. 2. 54 2. 57 2. 54 AS. (alter storage under tropical conditions)- 0.30 -0. 23 0. 19 m 2.36 2.36 2.40 ADmBX. (after storage under tropicalconditions) 0. 20 +0. 07 +0. 06

behind a green filter.

TABLE 2 G. of colloidal silver per mol of silver halide 0 0. 04 0. l6 0.64

2. 34 2. 33 2. 47 --0. 21 0. l7 --0. l1 2. 90 2. 94 2. 6G -0. 0. 02 0.01.

This table again clearly shows the stabilizing elfect of colloidalyellow silver. It reduces the maximum color density D of the freshmaterial to a slight extent but has no deleterious eilect on thespecific sensitivity S EXAMPLE 3 The procedure is the same as thatemployed in Example 2 except that g. of a white coupler of the formula 1(4 sulfophenyl)-3-heptadecyl-4-methyl-pyrazolone- (5) are added per kg.of emulsion in addition to 48 g. of the magenta-forming couplerpreviously mentioned.

TABLE 3 G. of colloidal silver per mol of silver halide 0 0. 20 0. 40

S, 2. 84 2. 72 2. 66 AS! (after tropical storage 0. 54 0. 48 -O. 13 m"2. 94 2. 92 2. 94 ADM; (after tropical storage) 0. 16 0. 22 0. 20

EXAMPLE 4 The procedure is the same as that employed in Example 1 exceptthat a silver iodobromide emulsion of medium sensitivity containing 4mol percent of AgI is used instead of the highly sensitive emulsion.

TABLE 4 G. of colloidal silver per mol of silver halide EXAMPLE 5 Theprocedure is the same as that employed in Example 4 with the exceptionthat various types of colloidal silver "re added to the mediumsensitivity cyan-forming layer to improve the stability under tropicalconditions. The materials are subjected once to a reversal developmentas in the previous examples and once to a conventional color negativedevelopment using a color developer of the following composition:

Benzyl alcohol ml 4.2 Sodium hexametaphosphate g 2 Sodium sulfiteanhydrous g 2 Potassium bromide g 1.5 Sodium metaborate cryst g 4 amino3 methyl N ethyl N (B methylsulfonamido ethyl) anilinosesquisulfatemonohydrate g 5 Made up with water to 1000 ml. pH l0.8i0.l.

Development temperature, 24 C. Development time, 12 minutes.

The relative sensitivity S achieved in colour negative development isindicated in log I 1 units measured at density 0.1 over the fog.

TABLE 5 Colloidal yellow Grey Nature of colloidal silver added silver 1brown 2 Black 3 G. of colloidal silver per mol of silver halide 0. 60 0.60 0. 60 Reversal development:

2. l9 2. 23 2. 10 A S! (after troplcal stcrag +0. 01 -0. 16 0. 20 ms;2. 1. 84 2. 14 2. l2 ADmsx. (after tropical storage), +0. 11 -0. 14 +0.01 0 Colour negative development:

S 3. 40 3. 30 3. 25 3. 15 A S (after tropical storage)-. 0. 42 +0. 12-0. 27 0 1 Prepared by Carey Leo. method.

According to D.B.P. No. 1,096,193, Example 1, but without blue blackparticles. tiglggcording to D.B.P. No. 1,096,193, Example 1 (with blueblack par- What is claimed is:

1. A color-photographic multilayer material having compounds thatproduce a negative image by imagewise exposure followed by developingtreatment or reversal treatment producing positive image comprising atleast one red-sensitized silver halide emulsion layer containing acyan-forming coupler, at least one green-sensitized silver halideemulsion layer containing a magenta-forming coupler and at least oneblue-sensitive silver halide emulsion layer containing a yellow-formingcoupler, wherein the improvement comprises at least one of the emulsionlayers of the group consisting of green-sensitized and redsensitizedemulsion layers comprises in the same phase a binder, a silveriodobromide colloidal silver and the color coupler.

2. A color-photographic material as claimed in claim 1 wherein saidcolloidal silver containing layer contains 0.02 to 0.8 :g. of colloidalsilver per mol of silver iodobromdie.

3. A color-photographic material as claimed in claim 1 wherein the saidcolloidal silver containing layer contains a gelatin binder and a yellowcolloidal silver.

References Cited UNITED STATES PATENTS 2,673,800 3/1954 Meeussen et al.9674 X 2,704,711 3/1955 Hanson, Jr. 9674 X 2,875,052 2/1959 Weyde 96683,206,310 9/1965 Herz 9667 3,211,552 10/1965 Chu 9674 DAVID KLEIN,Primary Examiner A. T. SURO PICG, Assistant Examiner U.S. Cl. X.R.96-22, 114.7

1. A COLOR-PHOROGRAPHIC MULTIAYER MATERAL HAVING COMPOUNDS THAT PRODUCEA NEGATIVE IMAGE BY IMAGEWISE EXPOSURE FOLLWED BY DEVELOPING TREATMENTOR REVERSAL TREATMENT PRODUCING POSITIVE IMAGE COMPRISING AT LEAST ONERED-SENSITIZED SILVER HALIDE EMULSION LAYER CONTAINING A CYAN-FORMINGCOUPLER, AT LAST ONE GREEN-SENSITIZED SILVER HALIDE EMULSION LAYERCONTAINING A MAGENTA-FORMING COUPLER AND AT LEAST ONE BLUE-SENSITIVESILVER HALIDE EMULSION LAYER CONTAINING A YELLOW-FORMING COUPLER,WHEREIN THE IMPROVEMENT COMPRISES AT LEAST ONE OF THE EMULSION LAYERS OFTHE GROUP CONSISTING OF GREEN-SENSITIZED AND REDSENSITIZED EMULSIONLAYERS COMPRISES IN THE SAME PHASE A BINDER, A SILVER IODOBROMIDECOLLODIAL SILVER AND THE COLOR COUPLER.